The present invention relates generally to tape storage systems. More specifically, the present invention relates generally to a tape storage system that uses tape cartridges and a method of transporting cartridges between a rack assembly and a tape drive of the tape storage system.
Automated tape storage systems are used for storing and retrieving relatively large amounts of information in digital form. One type of tape storage system includes a tape drive, a rack assembly that has one or more tape magazines, and a robotic cartridge handling mechanism. Each tape magazine typically holds a plurality of tape cartridges, which are retrieved from the tape magazines for usage in the tape drive. With this type of system, each tape magazine can include a plurality of tape cavities for holding the cartridges. The robotic cartridge handling mechanism individually retrieves one of the cartridges from one of the tape cavities and places the cartridge within the tape drive.
Such robotic cartridge handling mechanisms are often extremely complex. Typically, these mechanisms have to navigate around the rack assembly, moving between the tape drive and the desired cartridge in the rack assembly. Unfortunately, this type of system results in unnecessary waiting time, which can lead to decreased throughput of the system.
Additionally, robotic cartridge handling mechanisms have difficulty retrieving different sized cartridges. Such mechanisms have, in the past, only been able to accommodate one specific sized cartridge for transport between the tape drive and the rack assembly. This size limitation can necessitate the use of multiple automated tape storage systems, which can increase costs to the user. Further, having multiple systems can result in a more complicated system that is more difficult to maintain and service.
Another drawback of current storage systems involves the problem of servicing the tape drive without bringing the entire storage system to a standstill. Oftentimes, a tape drive may require repair or service, which can lead to taking the entire tape storage system offline. In other words, once the tape drive is removed from the system, the entire tape storage system is inoperable. In such instances, the information within the tape storage system become inaccessible, causing a substantial decrease in efficiency and throughput of the system.
Cartridge handling mechanisms have been developed to transfer cartridges between rack assemblies and tape drives without interfering with the operation of the tape drives. These cartridge handling mechanisms typically include a frame and a receiver that receives the cartridge. Unfortunately, existing cartridge handling mechanisms are not completely satisfactory. In particular, these cartridge handling mechanisms can take-up too much space within the storage system and/or require too much clearance to operate in the storage system. In addition, these cartridge handling mechanisms do not operate efficiently due to the time required to transport the desired cartridge between the tape magazine and the tape drive.
In light of the above, the need exists to provide an improved transport mechanism within a tape storage system that quickly and efficiently transfers a cartridge between a rack assembly and a tape drive. Another need exists to provide a rack assembly that eliminates the navigational requirements of the cartridge handling mechanism thereby decreasing transport waiting time, and increasing throughput of the tape storage system. Still another need exists to provide a tape storage system that utilizes different sized cartridges. Yet another need exists to provide a tape storage system that allows service or repair to the tape storage system without completely interrupting operation of the tape storage system. Still another need exists to provide a tape storage system that is relatively compact, has improved durability, and is relatively easy and cost efficient to manufacture and utilize.
The present invention is directed to a rack assembly of a tape storage system for use with a tape drive arrangement including a first tape drive, and a plurality of cartridges, that satisfies these needs. The rack assembly includes a rotatable magazine mount and a substantially circular cartridge magazine that is removably secured to the magazine mount. Additionally, the rack assembly includes a magazine mover that rotates the cartridge magazine. The magazine mount is typically rotatably secured to a housing base. The cartridge magazine can include at least twenty (20) tape cavities that each house one of the cartridges. The tape storage system also includes a first transport assembly that transports one of the cartridges between the cartridge magazine and the first tape drive.
The cartridge magazine rotates to position one of the tape cavities adjacent to the first transport assembly. At least a portion of the first transport assembly is typically positioned substantially between the housing base and the cartridge magazine. The first transport assembly includes a gripper assembly having a cartridge gripper that releasably secures one of the cartridges during transport between the cartridge magazine and the first tape drive.
The rack assembly can also include a second transport assembly that transports one of the cartridges between the cartridge magazine and a second tape drive. The second transport assembly is positioned adjacent to the first transport assembly. The first and second transport assemblies can transport two different sized cartridges from within the cartridge magazine to their respective tape drives, depending upon the requirements of the tape drives. Moreover, because both transport assemblies operate with the same cartridge magazine, the inoperability of one of the tape drives, i.e. for servicing or repair, will not result in taking the entire tape storage system offline.
Additionally, the present invention includes a method for transporting a cartridge between a cartridge magazine and a tape drive. The method includes the steps of providing a cartridge magazine, providing a transport assembly having a gripper assembly, positioning the cartridge between the gripper assembly and the tape drive, rotating the cartridge magazine to align the cartridge substantially between the gripper assembly and the tape drive, and gripping the cartridge with the gripper assembly. Additional steps include moving the gripper assembly to near the tape drive, and transferring the cartridge from the gripper assembly into the tape drive.